1. Field of the Invention
The present invention relates to a backlight module, and in particular to a direct backlight module that improves assembling efficiency and re-working efficiency.
2. The Related Arts
Liquid crystal displays (LCDs) have a variety of advantages, such as thin device body, low power consumption, and being free of radiation, and are thus of wide applications. Most of the liquid crystal displays that are currently available in the market are backlighting liquid crystal displays, which comprise a liquid crystal panel and a backlight module. The operation principle of the liquid crystal panel is that, with liquid crystal molecules interposed between two parallel glass substrates, a plurality of vertical and horizontal tiny wires is arranged between the two glass substrates and application of electricity is selectively carried out to control the liquid crystal molecules to change direction in order to refract out light emitting from the backlight module for generating images. Since the liquid crystal panel itself does not emit light, light must be provided by the backlight module in order to normally display images. Thus, the backlight module is one of the key components of a liquid crystal display. The backlight modules can be classified in two types, namely a side-edge backlight module and a direct backlight module, according to the position where light gets incident. The direct backlight module comprises a light source, such as a cold cathode fluorescent lamp (CCFL) or a light-emitting diode (LED), which is arranged at the backside of the liquid crystal panel to form a planar light source directly supplied to the liquid crystal panel.
Referring to FIG. 1, a conventional direct backlight module comprises: a backplane 100 and a backlight source 200 arranged inside the backplane 100. The backlight source 200 is mounted to a bottom board 102 of the backplane 100 and the backlight source 200 comprises a PCB substrate 202, wiring patterns 204 formed on the PCB substrate 202, and light-emitting diode (LED) lights 206 mounted to and electrically connected with the wiring patterns 204. However, such a structure of direct backlight module comprises a number of components and thus the manufacturing process is complicated.
Referring to FIG. 2, another conventional direct backlight module is shown. Backlight sources 200′ each comprise only wiring a pattern 204 and an LED light 206 mounted to and electrically connected with the wiring pattern 204. A bottom board 102 of a backplane 100 is provided with an electrical insulation layer 300 and the backplane 100 is made of a metallic material of high thermal conductivity. The backlight sources 200′ are directly mounted on the bottom board 102 of the backplane 100 via the electrical insulation layer 300. Such a structure of direct backlight module eliminates the use of a PCB substrate so that the components used are reduced, the manufacturing process is simplified, and the manufacturing cost is lowered down. Further, mounting the backlight sources 200′ directly on the bottom board 102 of the backplane 100 that is of high thermal conductivity via the electrical insulation layer 300 achieves a bettered effect of heat dissipation.
However, it is necessary to separately mount a plurality of backlight sources 200′ to the bottom board 102 of the backplane 100. The manufacturing efficiency is low. Particularly, when the LED light 206 of an individual backlight source 200′ is damaged and re-working is needed, re-working must be applied to the entire backplane 100 so that the re-working efficiency is extremely low.